Plug cap



June 13, 1939. G B,BENANDER 6 PLUG CAP Filed Jan. 22, 1935 Inventor:

7 George B.Benanden b x/ J Hi2 Attornqg.

V Patented June 13, 1939 PATENT. OFFICE PLUG CAP George B. Benander,Yalesville, Conn., assignor .to The Monowatt Electric Corporation, acorporation of Connecticut Application January 22, 1935, Serial No.2,915

5 Claims.

The present invention relates to plug caps and especially to rubbercovered plug caps adapted to be used with standard receptacles.

The object 'of the invention is to provide an improved rubber coveredplug cap which is simple and rugged in structure, reliable in operation,and may be manufactured at low cost.

In the drawing, Fig. 1 is a perspective view of an assembled plug cap;Fig. 2 is an exploded view of the plug cap shown in Fig. 1 and Fig. 3 isa side view, in cross section, of an assembled plug cap.

Referring to the drawing, the mounting block 40 formed of suitableinsulating material, such as a molded compound comprising an artificialresin and filler, is provided at one end with a curved transverse groove4| in one face and at its other end with a similar curved transversegroove 42 in the opposite face. Located in grooves 4i and 42 arecontacts 43. Each contactis provided with a recess 44 which provides astrap portion 45 and two spaced shoulders 46. 'The strap portion 45 iscurved to fit either groove 4| or 42 and when located therein the twoshoulders 46 engage opposite sides of the mounting block 40. Grooves 4|and 42 are of a depth such that the outer edges of strap portions 45 aresubstantially flush with the surfaces of the mounting block. Theportions of the contacts beyond the recesses 44 form prongs which areadapted to fit astandard plug receptacle.

The portion of the contacts back of the recess 44 form tabs in which.the binding screws 41 are held. At right angles to the ends of the tabsare flanges 43' which cooperate with the binding screws to hpldconducting wires in place. The shorting of the circuit by contact of thebinding screws is prevented by the finger 48 which lies between the twoscrews.

The mounting block and contacts as a unit fit in a flexible rubbercasing 50 leaving only the prongs exposed. The flanges 43' ofthecontacts rest on shoulders .53 in the casing. The casing is providedwith openings 5| which correspond in position with an opening 48 in themounting block when the unit is in place in the casing. The unit and thecasing are held together by a locking pin 52 which passes through thecorresponding openings. When the pin is in place, its ends are flushwith the surface of the casing. The pin fits the openings tightly enoughso that it is held in place by friction. Below the section shown at 55.Adjacent to me outer end of the casing is a bead 56 which reinforces theedge of said casing. Also the lower end of the neck 54 is reinforced bya bead 5'l.'

' To wire the plug cap for use, the cable is slipped through the neck ofthe casing and the wires contained in the casing are attached to thebinding posts 41. At this time, the contapts may or may not be assembledon the mounting block. After the wires are connected to the contacts andthe contacts have been mounted on the mounting block, the assembled unitcomprising the mounting block with the'contacts thereon is then pushedinto the casing until the flanges 43 rest on the shoulders 53 and theseveral openings 49 and 5| are in alignment. The pin 52 is then passedthrough the openings and the plug cap is ready for use. x

This construction has the advantage that it is simple in structure andcomposed of few parts,

permitting its manufacture at low cost. It can be taken apart readily inorder to repair or replace the cable and is easily assembled. The wiringis totally concealed by the mounting block, giving a neat appearing plugcap. The cap being flat sided facilitates locating the prongs in theproper relation to the slots in any receptacle.

By arranging grooves 4| and 42,0n opposite faces of the mounting block,the two contacts 42 maybe alike and interchangeable. The casing 50 holdscontacts 43 in grooves 4| and 42 in the mounting block but any strain orpull on thecontacts is taken by the mounting .block. I

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. A plug cap comprising an elongated rectanglar mounting block having agroove at each end, contacts having strap portions which fit saidgrooves and shoulders which engage the 40 mounting block at oppositeends of the grooves, a removable casing of yieldable material which fitsover the mounting block, and means for fastening the casing and blocktogether.

2. A plug cap comprising an elongated rectangular mounting block havinga groove at each end, contacts having strap portions whichflt saidgrooves and shoulders which engage the mounting block atopposite ends ofthe grooves,

a removable casing of yieldable material which fits over the mountingblock, and a pin for fastening the casing and block together.

3. A plug cap comprising a mounting block having at one end a groove onone side and at the other end a groove on the other side. con- Imounting block flts,,and means for limiting the tacts having portionswhich flt into said grooves and engage the block at the opposite ends ofthe grooves, and a removable casing which fits over said block. I a

4. A plug cap comprising a mounting block having at one end a groove onone side and at the other end a groove on the other side, contactshaving portions which fit into said grooves and engage the block atopposite ends of the grooves,

1 a'casing having an open end into which the

